A liver is a highly differentiated adenogenous organ which plays an important role in the intermediate metabolism of living body, and its function is sustained by hepatic parenchymal cells constituting this organ. In a rat, for example, it is known that even after surgical resection of about two-thirds of the liver the remaining hepatic tissue promptly grows and may be restored to its original size in about 10 days.
Based on the fact, patients suffering from hepatic carcinoma are often treated in such a way that the remaining normal hepatic tissue is allowed to proliferate after a partial hepatectomy.
A lot of researches and investigations have been pursued to elucidate the mechanism of the foregoing proliferation of the liver (hepatic regeneration). According to such studies, it was suggested that some growth promoting factor might appear in the blood of hepatectomized rat, and there have been several reports on the success in a partial purification of the same factor (rat hepatocyte growth factor: rHGF). However, the rHGF preparations reported have diversity with respect to molecular weight and other physicochemical properties, and remain to be clarified in many respects. As yet, there has been no report demonstrating the presence of a similar hepatocyte growth factor in a human blood.